Abstract
1. The chondroitinsulpf uric acid of cartilage was estimated and calculated in percentages of dry powder. The results may be summarized as follows:
a) The content of the chondroitinsulfuric acid varies according to the sort of cartilage ; namely, the hyaline cartilage of the grown-up but not old animal contains the biggest, the fibrocartilage the smallest amount and the elastic cartilage lies between these two sorts.
The costal cartilage makes an exception, because of early commencement of ossification in it.
b) The soft part of the hyaline cartilage is richer in the acid than the hard ossifying part is.
1) The colour depth corresponded to about_??_times that developed by 1mg chondrosamine chlorhydrate.
c) The acid of the hyaline cartilage increases with age; in other words, with the ossification.
2. The acid in question appears in bone in rickets in accord with the process of chondrification.
3. The reduction method may be made use of for measurement of the chondroitinsulfuric acid in cartilage, when not so exact a value is desired. The amount of the dry cartilage powder necessary for this purpose is as small as 1mgm.
In conclusion, I should like to express my best thanks to Professor K. Kodama for his helpful advice and criticism; to Dr. I. Kubo, Professor of Otorhinolaryngology for encouragement, and to Assistant Professor H. Masasmune for kind direction during the Whole course of this investigation.
